Immunohistochemical expression of SHH, PTC, SMO and GLI1 in glandular odontogenic cysts and dentigerous cysts.

To investigate expression of the sonic hedgehog (SHH) signaling pathway components in glandular odontogenic cysts (GOCs), and dentigerous cysts (DCs). Immunohistochemical staining for SHH, patched (PTC), smoothened (SMO), and the transcriptional factor GLI1 were investigated in the 12 GOCs specimens and 20 DCs. In GOCs and DCs, immunoreactivity for SHH, PTC, SMO, and GLI1 were detected in the epithelial cytoplasm. Each of the genes of the SHH signaling pathway was expressed in similar patterns in the epithelial lining of the cysts. The expression of SHH, PTC, SMO, and GLI1 was significantly higher in epithelia than that of subepithelial fibroblasts (P < 0.01). No statistical difference among the labeling index of the epithelial lining among the different cyst types could be revealed. The findings suggest that the proteins of the SHH signaling pathway are predominantly located within the epithelial components of GOCs and DCs. SHH signaling pathway may play a role in epithelial lining formation.